Methods and compositions of piperazine-based viscoelastic surfactants as diversion agents

Abstract

A wellbore fluid including a first surfactant, a second surfactant, an activator and an aqueous base fluid is provided. The first surfactant has a structure represented by Formula (I):where Y1, Y2, Y3, Y4 are each, independently, a sulfonate, a carboxylate, an ester or a hydroxyl group, m is an integer ranging from 2 to 3, and n, o, and k are each, independently, integers ranging from 2 to 10. The second surfactant has a structure represented by Formula (III):where R2 is a C15-C27 hydrocarbon group or a C15-C29 substituted hydrocarbon group, R3 is a C1-C10 hydrocarbon group, and p and q are each, independently, an integer ranging from 1 to 4. A method of using the wellbore fluid for treating a hydrocarbon-containing formation is also provided.

What is claimed is: 
     
       1. A wellbore fluid, comprising:
 a first surfactant having a structure represented by Formula (I): 
 
       
         
           
           
               
               
           
         
         wherein Y 1 , Y 2 , Y 3 , Y 4  are each, independently, a sulfonate, a carboxylate, an ester or a hydroxyl group, m is an integer ranging from 2 to 3, and n, o, and k are each, independently, integers ranging from 2 to 10; 
         a second surfactant having a structure represented by Formula (III): 
       
       
         
           
           
               
               
           
         
         wherein R 2  is a C 15 -C 27  hydrocarbon group or a C 15 -C 29  substituted hydrocarbon group, R 3  is a C 1 -C 10  hydrocarbon group, and p and q are each, independently, an integer ranging from 1 to 4; 
         an activator; and 
         an aqueous base fluid. 
       
     
     
       2. The wellbore fluid according to  claim 1 , wherein the first surfactant has a structure represented by formula (II): 
       
         
           
           
               
               
           
         
       
     
     
       3. The wellbore fluid according to  claim 1 , wherein the second surfactant has a structure represented by formula (IV): 
       
         
           
           
               
               
           
         
       
     
     
       4. The wellbore fluid according to  claim 1 , comprising 1 to 15 wt. % of the first surfactant. 
     
     
       5. The wellbore fluid according to  claim 1 , comprising 1 to 15 wt. % of the second surfactant. 
     
     
       6. The wellbore fluid according to  claim 1 , comprising 5 to 30 wt. % of the activator. 
     
     
       7. The wellbore fluid according to  claim 1 , further comprising an acid. 
     
     
       8. The wellbore fluid according to  claim 1 , wherein the activator is CaCl 2 ). 
     
     
       9. The wellbore fluid according to  claim 1 , wherein the wellbore fluid has a viscosity at 90° C. ranging from 150 to 400 cP.